SHENZHEN • Former world No. 1 Maria Sharapova's Australian Open preparations suffered a blow after a thigh injury forced her to retire from her Shenzhen Open quarter-final clash against Aryna Sabalenka yesterday.

Sharapova struggled to move on court and conceded the opening set 6-1, with coach Thomas Hogstedt urging the Russian to take her game to the next level or call for a medical time-out.

"If you feel more like you did on the first point, then you just stop. Or you take a medical now," he said. "But the shots are there... You have to get it up to another gear."

After receiving treatment off-court between sets, Sharapova sprinted out of the blocks to record a service hold and then pushed Sabalenka in the next game, creating three break-point opportunities.

Sabalenka, however, turned things around to move 4-2 ahead before her Russian opponent found herself unable to continue and retired from the match.

"I think we both played well - and then she got injured," said the Belarusian afterwards. "Hopefully she will get well soon."

Sharapova, who won the Australian Open in 2008, tasted Tianjin Open success in 2017 after a 15-month doping suspension but has endured a difficult run at the Grand Slams.

World No. 13 Sabalenka will face China's Wang Yafan for a spot in the Shenzhen final, while American Alison Riske faces Russia's Vera Zvonareva in the other semi-final.

The Australian Open begins in Melbourne on Jan 14.

In Perth, Germany will meet Switzerland today in a repeat of last year's Hopman Cup final, after downing Australia 2-1 yesterday.

Angelique Kerber got the German team off to a winning start, beating Ashleigh Barty 6-4, 6-4 before Alexander Zverev matched her by defeating Matthew Ebden 6-4, 6-3 in straight sets. The Australian pair got one back over their counterparts in the mixed doubles with a 4-0, 4-3 (5-1) win.

REUTERS